I have a Norvel BigMig .061 RC engine, and I have a couple of questions for anyone who can help.

When breaking in the engine, should the throttle be fully opened, full closed, or somewhere in the middle?

If I start with the needle valve at about 2 1/2 turns open, is closing the valve making the engine run more rich or lean?

What is the purpose of the small screw just aft the needle valve, and how should I go about adjusting it?

The muffler that came with my engine is connected by a little bent wire that goes around the engine and holds it in place. However, it does not hold it too tightly, and the muffler does not stay exactly over the exhaust. Is there something I should do about this, or do I even need the muffler?

And finally, I've read about the importance of having a pressurized fuel tank, and from what I read, I understand that to mean that the engine runs best when air is being forced into the tank, which in turn forces the gas into the engine. However, I've noticed that my engine runs best when I have the vent line on the fuel tank plugged up allowing no air to go into the tank. (This seems to work better than running the exhaust line to the top of the muffler.) What is going on here, and is that bad for my engine?

Thanks in advance for any help you can give.

-chris

For braking your engine in, the throttle should be fully open.

2 1/2 turnes should be right. Just make sure you are NEVER too lean.

The little screw is your idle screw. It should be fine the way it is.

I have never used this engine myself (only watched) so I cant tell you about the muffler.

Taking up where MasterSmasher left off:

Turn the neele inwards to make the engine leaner (closing the valve, reduces fuel flow, which makes a leaner run).

Norvell BigMigs are known for the annoying muffler mounting arrangement. Jurry rig as necessary to get it to stay in place. If I recall, they have a gasket that should be in there to take up some of the space. A lot of guys go at it with high-temp RTV (from your local autoparts store) to make a gasket and seal it up. I've seen guys make muffler mounting straps from nose clamps for the Norvels as well. If you have a field that allows you to run with out the muffler, then, yes, you can do it. It's loud though.

Plugging up the tank isn't really a great idea. You will cause a lean run, as the fuel is pulled from the tank something has to get in there to fill the vacume. So the engine will find itself pulling harder and harder to draw fuel as the fuel level goes down. However, I have seen the Norvels run better when really small fuel tubing was used for the muffler vent line, apparently sometimes, they don't like the fuel to be too pressurized from the tank. Try leaving the vent line open but not attached to the muffler.

I've also not run this particular engine, but I've seen lots of BigMigs with the above issues.

Chris, do yourself a favour and ask the same question in the 1/2a and 1/8a forum. There are many guys in there that are experts on the small norvel engines.

Good luck

Christie